1. Area of the Art
The present invention is in the area of agriculture and more specifically is directed to a method for improving the culture of the edible common fig (Ficus carica)
2. Description of the Prior Art
Not unsurprisingly, culture and sale of fruits is of considerable economic importance. Traditional northern hemisphere fruits such as pears and apples have long been American staples. Today, more than ever, people recognize the truth in the old saying: “An apple a day keeps the doctor away.” Increasingly, the public's taste is turning to what used to be considered “exotic” fruits. The trend probably started with the successful exploitation by New Zealand growers of the Chinese gooseberries (Actinidia sp.) after cleverly renaming them “Kiwi Fruit.” Prior to the Kiwi success the most successful “exotic” fruit was probably the avocado (Persea sp.). Again, this success was probably helped by marketing under the Spanish name (avocado) as opposed to the less tasty sounding English name, “alligator pear.”
One is increasingly seeing successful marketing of other “exotic” fruits such as the tamarillo (Cyphomandra hartwegi), and the African horned melon (Cucumis metuliferus) which definitely seems to sell better when named “Kiwano®.” Along with this trend to popularize new fruits, several older “exotic” fruits are also becoming increasingly popular. Japanese persimmons (Diospyros kaki) are being seen more often in the autumn market as are pomegranates (Punica granatum) a plant from Asia Minor whose near-eastern history dates back to the chalcolithic period, some 6000 years ago.
The edible common fig (Ficus carica), another fruit of biblical and classical history, seems poised to make a comeback. Figs have long been valued in warm Mediterranean countries as a delicious fruit, available during the late summer (July-September). Although it can be grown as a curiosity in many of the southern states of the U.S., commercial culture seems feasible only in the western states of the U.S.—particularly in the warmer valleys of California. As currently grown in California, the fig tends to have a rather short season so that fresh fruit is available only sporadically. Despite considerable acreage devoted to figs in California, this fruit is largely known in the United States only in its dried form (today usually as the ubiquitous fig bar or fig cookie). Prior to the advent of the modern supermarket with year round fruits and vegetables, consumers expected and appreciated dried fruit. Most of the California fig crop was dried and additional substantial quantities of dried figs were imported. These days, dried fruit is generally not appreciated, and because fresh figs are soft and often do not ship well, many consumers have never even tasted one. This is unfortunate because the fruit is not only delicious but contains an unusually high level of antioxidant compounds which are believed to be beneficial to human health.
The fig is believed to be indigenous to western Asia and to have been distributed by man throughout the Mediterranean area. The fig tree has an unusual growth, bloom, and fruiting cycle. The tiny flowers of the fig are out of sight, clustered inside the green “fruits”, technically a synconium. Pollinating insects gain access to the flowers through an opening at the distal end of the synconium. Unlike temperate trees that have a single blooming season and often produce buds for spring flowering, the summer or autumn before, the fig continually produces flower buds during the growth season. Under temperate growth conditions, the common fig produces a number of flower buds in autumn; these buds then over winter and produce a first spring fruit crop (called brebas or breba figs). In cold climates, the brebas crop is often destroyed by spring frosts. The brebas are borne on the previous year's or “old” wood. The second fruit crop or main crop is borne in the late summer and fall on growth produced during the current season.
In the case of modern varieties of the common fig, the flowers are all female and produce a fruit without a need for pollination (i.e., the flowers are parthenocarpic). There are three other fig types: 1) the caprifig which has both male and female flowers and requires pollination by a tiny wasp, Blastophaga grossorum; 2) the Smyrna fig, which does not produce viable pollen and requires cross-pollination by caprifigs to develop normal fruit; and 3) the San Pedro fig which is intermediate with its first crop independent of pollination like the common fig, and its second crop dependent on pollination.
Edible figs are produced on a deciduous tree that may range in height from 10 to 50 feet depending on pruning and growth conditions. Left to their own devices the plants often grow as a thicket with multiple trunks. However, the plant can be readily espaliered or otherwise trained although there appears to be many opinions about optimal shapes of the trained tree. The trees can withstand some cold weather but when exposed to prolonged freezing conditions, the trees die back to their roots. In optimal growing regions, with little or no exposure to freezing temperatures, the trees can become huge and shade out anything growing beneath them. It seems to be the general belief that pruning to control size must be done with care because it results in loss of fruit. It has been generally believed that heavy pruning is essential only during the initial years of tree growth.
It will be appreciated that the growth characteristics of the fig make it specially amenable to cultural manipulations. The marketing triumph of Chinese gooseberries mentioned above was the result of improved agricultural practices as well as marketing savvy. Significant agricultural improvements have been applied to many other fruits. With the current boom in wine production it is not surprising that considerable attention has been paid to the scientific cultivation of the grape vine. A good older example is found in U.S. Pat. No. 4,291,526 to Hiyama et al. which describes a mechanical harvesting system for the grape. U.S. Pat. No. 6,374,538 to Morris et al. describes a more modern method for mechanizing grape production. U.S. Pat. No. 6,578,318 to Clark, describes an improved method of grape culture including pruning and arrangement of the plant's canes.
Besides the methods described above for viticulture, a number of technologies can be used to improve the culture of other fruits. U.S. Pat. No. 4,336,667 to Evans discloses a pruning and training cultivation system applicable to a variety of fruit trees. U.S. Pat. No. 5,295,324 to Baba et al. discloses the use of a special plastic sheet mulching material to modify and control the growth and quality of fruits and vegetables including tree fruit.